Aria "Jesus schläft, was soll ich hoffen" aus der Kantate BWV 81

As a teenager I found the alto arias awful, endlessly long and boring, even in the Christmas Oratorio there is a "terrible" alto aria where Mary moves something in the heart. But with age comes feeling, sensation and recognition of the beautiful. In this cantata BWV81, Bach lets the alto voice begin, with what I think is a very moving aria that once again underscores Bach's fantastic tonal language. There is a great deal of counterpoint, playing with the minor scale, the leading note in the harmonic minor, even in the descent. Very impressive is bar 25, which with the text "mit erblasstem Angesicht schon des Todes Abgrund offen?" a quaver movement downward in ALL VOICES!
Remarkable also the conclusion of the voice: "What shall I hope?" harmonically absolutely open, it is not a conclusion on the keynote but one in the middle of the cadence and in the middle of the measure. Incredible.
The piece is for 1 alto voice, 2 recorders, violins 1 and 2, viola and basso continuo.

Altstimme:
Solowerk: Trompette en chamade 8", Jubalflöte 8" und Trichterflöte 4"
Blockflöte 1+2:
Hauptwerk: Holzflöte 8", Rohrflöte 8" und Spitzflöte 4"
Streicher:
Schwellwerk:V.Celeste 8",Viola 8", Gedackt 8" und Plein jeu 2"
Basso Continuo:
Pedal (mit Schwell und Hauptwerk gekoppelt): Subbass 16"